Limited Chain Relay With Virtual Peer for Multimedia Distribution

ABSTRACT

A method includes at a first customer premises equipment (CPE) device coupled to a multimedia distribution network, generating a first request for multimedia content. The method also includes sending the first request to a network node of the multimedia distribution network. The method further includes receiving the multimedia content from a virtual peer located at the network node and storing the multimedia content at the first CPE device. The method also includes receiving a message via the multimedia distribution network, the message indicating a transmission of a second request for the multimedia content by a second customer premises equipment (CPE) device. The method further includes transmitting at least a portion of the stored multimedia content to the second CPE device.

FIELD OF THE DISCLOSURE

The present disclosure is generally related to providing a limited chainrelay with at least one virtual peer for multimedia distribution.

BACKGROUND

Multimedia content distribution networks encompass conventional cable,satellite, and wired and wireless packet-switched networks includingpeer-to-peer (P2P) networks. The bandwidth required to transmitmultimedia content, such as video-on-demand (VOD), can be especiallytaxing on bandwidth limitations inherent in content distributionnetworks. Existing techniques for distributing on-demand content andother types of multimedia content include multicasting, unicasting,distributed caching, and P2P striping.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a particular embodiment of a multimediacontent distribution network;

FIG. 2 is a block diagram of a particular embodiment of a customerpremises equipment (CPE) device;

FIG. 3 is a block diagram of a particular embodiment of a network node;

FIG. 4 is a block diagram of a particular embodiment of a virtual peer;

FIG. 5 depicts an embodiment of limited chain relay (LCR) distributionhaving a virtual peer at a network node;

FIG. 6 depicts an embodiment of LCR distribution involving a helpervirtual peer;

FIG. 7 is a flow diagram of a particular embodiment of a method ofdistributing multimedia content;

FIG. 8 is a flow diagram of a particular embodiment of a method ofevaluating an uplink of a CPE device;

FIG. 9 is a flow diagram of a particular embodiment of a method ofproviding a limited chain relay (LCR) with at least one virtual peer formultimedia distribution; and

FIG. 10 is a block diagram of an illustrative embodiment of a generalcomputer system.

DETAILED DESCRIPTION

The various embodiments disclose a system and method to provide alimited chain relay (LCR) with at least one virtual peer for multimediadistribution. A set of virtual peers may be provided at a network nodeof a multimedia distribution network. One or more virtual peers may becoupled to one or more network nodes of the multimedia distributionnetwork. The storage capacity and the uplink capacity of one or more ofthe virtual peers may be used in the distribution of multimedia content.The set of virtual peers may implement the limited chain relay (LCR)functions of peer storage and uploading to a peer and related controlfunctions so that the whole scheme is under the control of themultimedia distribution network. This may eliminate uncertaintiesrelated to peer availability, peer storage availability, and peer uplinkbandwidth capability that may be present in a peer-to-peer (P2P)implementation of an LCR algorithm.

In a particular embodiment, a method is disclosed that includes, at afirst customer premises equipment (CPE) device coupled to a multimediadistribution network, generating a first request for multimedia content.The method also includes sending the first request to a network node ofthe multimedia distribution network. The method further includesreceiving the multimedia content from a virtual peer located at thenetwork node and storing the multimedia content at the first CPE device.The method also includes receiving a message via the multimediadistribution network, the message indicating a transmission of a secondrequest for the multimedia content by a second customer premisesequipment (CPE) device. The method further includes transmitting atleast a portion of the stored multimedia content to the second CPEdevice.

In another particular embodiment, a customer premises equipment (CPE)device suitable for use in a multimedia content distribution network isdisclosed. The CPE device includes a processor and a computer readablestorage medium accessible to the processor. The CPE device also includesa network interface for receiving multimedia content. The CPE devicefurther includes a decoder for processing the multimedia contentreceived via the network interface. The computer readable storage mediumincludes instructions comprising a limited chain relay (LCR)application. The LCR application generates a first request for themultimedia content and sends the first request to a virtual peer via anetwork node of the multimedia content distribution network, where thenetwork node is coupled to a server. The LCR application receives themultimedia content from the virtual peer via the network node and storesthe received multimedia content. The LCR application receives a messageindicating a transmission of a second request for the multimedia contentby second customer premises equipment (CPE). In response to receivingthe message, the LCR application transmits at least a portion of thestored multimedia content to the second CPE device via the network node.

In another particular embodiment, a network node suitable for use in amultimedia content distribution network is disclosed. The network nodeincludes a processor and a computer readable storage medium accessibleto the processor. The network node also includes a network interface forreceiving multimedia content. The computer readable storage mediumincludes instructions comprising a limited chain relay (LCR)distribution application. The LCR distribution application determines abeginning and ending of successive LCR time intervals. In response todetecting a first request during a first LCR time interval, where thefirst request is for the multimedia content, the LCR distributionapplication transmits at least a portion of the multimedia content to afirst customer premises equipment (CPE) device. In response to detectinga second request during the first LCR time interval, where the secondrequest is also for the multimedia content, the LCR distributionapplication sends a message to the first CPE device instructing thefirst CPE device to transmit at least a portion of the multimediacontent from the first CPE device to a second customer premisesequipment (CPE) device.

Referring to FIG. 1, a block diagram of selected elements of aparticular embodiment of a multimedia content distribution network isdepicted and generally designated 100. The multimedia contentdistribution network 100 exhibits a hierarchical architecturalarrangement with an upstream video server (UVS) 102 residing at thehierarchical “top” of the multimedia content distribution network 100.The UVS 102 includes resources to acquire, process, and transmitbroadcast content and video-on-demand (VOD) content. As depicted in FIG.1, the UVS 102 represents the primary acquisition and aggregationresource for national interest programming. In some embodiments, the UVS102 serves as a super headend office (SHO).

The UVS 102 may distribute acquired content via a backbone network 104to one or more downstream video servers (DVSs) 110. The DVSs 110represent video distribution points within each designated market area(DMA). In some embodiments, each DMA may be served by a correspondingDVS 110. In some embodiments, the UVS 102 unicasts or otherwisetransmits VOD content to all DVSs 110. The DVSs 110 may include theirown content acquisition resources, and the DVSs 110 may serve asacquisition resources for regional or local content includingadvertising, local broadcast channels, municipal channels, and the like.In some embodiments, one or more of the DVSs 110 may be implemented as avideo hub office (VHO).

The multimedia content distribution network 100 further includesdownstream network nodes (DNNs) 120 located downstream of the DVSs 110,between the DVSs 110 and end user customer premises equipment (CPE)devices or CPE devices 140. The physical network connecting the CPEdevices 140 to the DNN 120 is referred to as the access network 130,which includes “last mile” links 135. The last mile links 135 mayinclude DSL-compliant unshielded twisted pair copper, fiber opticcables, or a combination of both. Other embodiments of the multimediacontent distribution network 100 may employ intermediate offices (notshown) between the DNNs 120 and the DVSs 110 to reduce the number ofdirect connections to any one of the DVSs 110. In an alternativeembodiment, the CPE devices 140 may be connected to the DNN 120wirelessly, with the DNN 120 corresponding to a cell tower or some nodeabove the cell tower.

The multimedia content distribution network 100 also includes one ormore virtual peers (VPs) 190. The VPs 190 may be located at the DNNs 120and may be coupled to the DNNs 120, as shown in FIG. 1. The VPs 190provide similar functionality to the functionality provided by the CPEdevices 140, which are also known as peers. Like a peer, a VP mayimplement the limited chain relay (LCR) functions of storage ofmultimedia content and of uploading the stored multimedia content to apeer upon request by the peer. A VP may have greater storage capacitythan a peer and may have greater uplink capacity than a peer. Like apeer, a VP may serve as a “helper” in an implementation of an LCRalgorithm. Unlike a peer, a VP may not request a particular program ofmultimedia content (PMC) and may not decode or display the PMC.

In some embodiments, the DNNs 120 may include packet routing capability,such as the packet routing capability that would be found in aconventional router of an IP-based network. In this case, multimediacontent may be transferred between network elements that are downstreamof the DNNs 120 including, for example, between the CPE devices 140,without invoking media delivery services of the DVSs 110 or any networkelement upstream of the DVSs 110. The DNNs 120 shown in FIG. 1 includepacket routing resources or routers 122 that support packet routing.

Depending on the implementation, the DNN 120 may represent a centraloffice (CO) or a digital subscriber line access multiplexer (DSLAM)connected to a CO. In a DSLAM implementation of the DNN 120, the DSLAMmay include the routers 122. In other embodiments, the routers 122comprise a portion of a CO. In either of these embodiments,communication between the CPE devices 140 consumes bandwidth andresources downstream of the CO but does not consume bandwidth orresources upstream of the CO.

When an access network 130 includes a fiber-to-the-home access network,the DNN 120 may represent a CO and the last mile link 135 may representa passive optical network (PON) that connects directly to an end user'sCPE device 140. Alternatively, in a fiber to the node (FTTN) deployment,fiber connections connect the COs with the DSLAMs while unshieldedtwisted copper pairs connect the DSLAMs to the CPE devices 140. The DNN120 represents the most-downstream network node that incorporates therouters 122, whether that node is a CO, a DSLAM, or another type ofnetwork node.

The CPE devices 140 as shown in FIG. 1 represent an element of a homenetwork 150 portion of the multimedia distribution network 100. In aparticular embodiment, the home network 150 includes a residentialgateway (RG) 170 including a digital subscriber line (DSL) modemsuitable for use in FTTN implementations of the access network 130. Infiber to the premises (FTTP) implementations of the access network 130(not shown), the home network 150 may include an optical-to-Ethernetnetwork termination (ONT).

The RG 170 provides a managed interface between the CPE device 140 andservices delivered over the network infrastructure. The RG 170 may alsoimplement a session initiation protocol (SIP) client for voice over IP(VoIP) service. The RG 170 may terminate the broadband connections androute traffic to local area network (LAN) devices on the premises. IPservices in the home may be accessed via the RG 170. Networking withinthe home may use different technologies including, as examples, Ethernetover COAX, Ethernet over home phone-line network alliance (HPNA), wired(802.3), and wireless (802.11a/b/g).

The bandwidth available on each last mile link 135 is dependent upon theimplementation. In an FTTN implementation as shown in FIG. 1, assumingthe RG 170 has sufficient disc space (e.g., 100 Gigabytes or Gbytes),typical multimedia streaming rates are 2 Megabits per second or Mbps forstandard definition (SD) and 6.5 Mbps for high definition (HD). A VODasset is streamed at a minimum of the SD rate. A DSLAM may support up to200 homes. The farther a home is from the DSLAM, the lower its observedbandwidth. Implementing a configuration that supports two HD channels,two SD channels, one high speed internet data channel (6 Mbps) and oneVoIP channel (2 Mbps) may be accomplished with a 25 Mbps link.

In some embodiments, video services are provided by the end user CPEdevice 140. The CPE device 140 may represent a standalone set-top boxdevice (STB) connected to a television or display device 160. In otherembodiments, the CPE device 140 may be integrated into the RG 170, thedisplay 160, or any combination thereof. The CPE device 140 processesmultimedia content and renders the multimedia content for display on thedisplay 160.

An example representative of the above architecture is a service where aVHO serves a set of COs that are each coupled to several DSLAMs. EachDSLAM serves a multitude of homes, each of which has a STB connected toone or more television sets. In this architecture, videos aretransmitted to the DSLAM over fiber and then by the DSLAM to the homeSTB using asymmetric digital subscriber lines (ADSL) over a twisted pairof copper. The transmission to the home occurs over a downlink datachannel (Down Link), while requests for video and other control data aresent from the home STB to the VHO via an uplink channel (Up Link). Thedownlink is shared by a variety of applications such as broadcast video,VOD, and data. The uplink is similarly shared by various control data(for example, VOD requests) and user data (data, still pictures, user'svideo clips, and the like).

Specific challenges in the area of video distribution are the availableuplink and downlink capacities and rates in the access portion of thenetwork (e.g., the access network 130 of FIG. 1). This is the section ofthe network between the video server and the CPE device. In mostarchitectures, the uplink rate is significantly smaller than thedownlink rate.

In addition to the link constraints, some embodiments consider theavailable storage capacity and other storage restrictions at the digitalvideo recorder (DVR) which may be used by the consumer for recordingboth broadcast video as well as VOD content. The content distributiontechniques disclosed herein may also use that recording capacity tosupport other consumers' need for the multimedia content. Depending onthe implementation and subject to copyright restrictions, either all oronly a portion of the multimedia content may be stored in the CPEdevice. The content distribution techniques disclosed herein mayencompass multimedia content distribution approaches that do not permitor necessarily require the receiver to store the entire multimediacontent.

In various embodiments, one or more of the VPs 190 may be coupled to oneor more of the DNNs 120 of the multimedia distribution network 100. Thestorage capacity and the uplink capacity of the VPs 190 may be used inthe distribution of multimedia content. The VPs 190 may implement thelimited chain relay (LCR) functions of peer storage and uploading to aCPE device 140 and related control functions so that the LCR algorithmis under the control of the multimedia distribution network 100. Thismay eliminate uncertainties related to CPE device 140 availability, CPEdevice 140 storage availability, and CPE device 140 uplink bandwidthcapability that may be present in a peer-to-peer (P2P) implementation ofan LCR algorithm.

Referring to FIG. 2, a block diagram of selected elements of aparticular embodiment of the CPE device 140 of FIG. 1 is depicted. TheCPE device 140 includes a processor 201 coupled via a shared bus 202 tostorage media collectively identified as storage 210. The processor 201may be a general purpose microprocessor such as an x86 type processor.In other embodiments, the processor 201 may be implemented with any ofvarious, commercially distributed embedded processors. The storage 210encompasses persistent and volatile media, fixed and movable media, andmagnetic and semiconductor media. The storage 210 is operable to storeinstructions, data structures, or any combination thereof. Sets ofinstructions stored in the storage 210 may be referred to as computerprograms, application programs, software, and other terms that will befamiliar to skilled artisans. Moreover, although the storage 210 isshown in FIG. 2 as an element of the CPE device 140, the storage 210 mayinclude portions that are distributed, network hosted, or otherwiseremotely located from the CPE device 140.

The CPE device 140 as shown in FIG. 2 further includes a network adapter220 through which the CPE device 140 receives and transmits multimediacontent. In embodiments employing IP-based networks, multimedia contentmay be delivered to the CPE device 140 as a series of IP-compliantpackets. In other embodiments, including digitally modulated cable-basedembodiments of the access network 130 of FIG. 1, the multimedia contentmay be modulated into a particular frequency band and transportedsimultaneously with multimedia content from other “channels,” which aremodulated into their own respective carrier bands.

The CPE device 140 includes a decoder 240. Multimedia content may bedigitally compressed, encrypted, modulated, packetized, or otherwiseformatted as it is received from the access network 130 of FIG. 1. Thedecoder 240 is configured to process incoming multimedia content togenerate a native format video stream 242 and audio stream 244. For usewith IP-based implementations of the access network 130, the decoder 240may include transport/demultiplexing resources 230 to convert a seriesor set of IP-compliant packets into a video stream 232 and an audiostream 234. For use with cable-based embodiments of the access network130, the decoder 240 may include one or more tuners to extract a desiredstream of multimedia content by filtering a desired frequency band.

The decoder 240 is further configured to decrypt, descramble,decompress, or any combination thereof, multimedia content to generatenative format video stream 242 and audio stream 244. The decompressionperformed by the decoder 240 may comply with any of various videocompression/decompression algorithms including, as examples, algorithmssuitable for use with any of the H.264, Motion Picture Expert Group(MPEG), or Windows® Media Video (WMV) compression formats including, asexamples, MPEG-2, MPEG-4, WMV 7, WMV 8, and WMV 9. Similarly, thedecoder 240 may employ any of various audio decoding algorithmsincluding Dolby® Digital, Digital Theatre System (DTS) CoherentAcoustics, Advanced Audio Coding (AAC), MP3, and Windows® Media Audio(WMA).

The native format video stream 242 and audio stream 244 shown in FIG. 2may be processed by encoders/digital-to-analog converters(encoders/DACs) 250 and 260 respectively to produce analog video signal252 and audio signal 254 in a format compliant with television/display126. The television/display 126 may comply with a National TelevisionSystems Committee (NTSC) standard, a Phase Alternating Line (PAL)standard, or any other suitable television standard.

The storage 210 shown in FIG. 2 includes software in the form of anoperating system (OS) 212, an LCR client application (LCR client app)214, and a virtual peer (VP) logic module 290. The OS 212 may representa Unix or Unix-like operating system, a Windows® family operatingsystem, or another suitable operating system. In some embodiments, theLCR client application 214 includes instructions that, when executed,cause at least one of the CPE devices 140 to receive multimedia contentfrom at least one of the VPs 190 of FIG. 1 and cause two or possiblymore of the CPE devices 140 to deliver multimedia content from at leastone of the CPE devices 140 to at least one other of the CPE devices 140.In some embodiments, the delivery of multimedia content takes placeentirely over a portion of the multimedia distribution network 100 ofFIG. 1 that is downstream of the DNNs 120. In some embodiments, the LCRclient application 214 generates a first request for the multimediacontent and sends the first request to the VP 190 via the DNN 120 of themultimedia content distribution network 100. The LCR client application214 receives the multimedia content from the VP 190 via the DNN 120 andstores the received multimedia content, receives a message indicating atransmission of a second request for the multimedia content by a secondCPE device 140, and, in response to receiving the message, transmits atleast a portion of the stored multimedia content to the second CPEdevice 140 via the DNN 120.

In some embodiments, the VP logic module 290 includes instructions that,when executed, cause the CPE device 140 to receive multimedia contentfrom one or more of the VPs 190 of FIG. 1. The VP logic module 290coordinates the interactions of the CPE device 140 with one or more ofthe VPs 190. In alternative embodiments, the LCR client application 214may be included in the VP logic module 290.

Referring to FIG. 3, a block diagram of selected elements of aparticular embodiment of the DNN 120 of FIG. 1 is depicted. The DNN 120includes a processor 301, storage media identified as storage 310, and anetwork interface adapter or NIC 320. The processor 301 and the NIC 320connect to a shared bus 305 that provides access to the storage 310. Thestorage 310 encompasses persistent and volatile media, fixed andremovable media, and magnetic, optical, and semiconductor media. Thestorage 310 may include database structures, processor executableinstructions, or any combination thereof. The instructions embedded orotherwise stored in the storage 310 include an operating system (OS)325, an LCR distribution application 350, and a VP logic module 390. TheOS 325 may be a Unix or Unix-like operating system, a Windows® familyoperating system, or another suitable type of operating system.

The LCR distribution application 350 determines a beginning and endingof successive LCR time intervals. In response to detecting a firstrequest during a first LCR time interval, where the first request is formultimedia content, the LCR distribution application 350 transmits atleast a portion of the multimedia content from a VP 190 to the first CPEdevice 140. In response to detecting a second request during the firstLCR time interval, where the second request is also for the samemultimedia content, the LCR distribution application 350 sends a messageto the first CPE device 140 instructing the first CPE device 140 totransmit at least a portion of the multimedia content from the first CPEdevice 140 to the second CPE device 140. Although the LCR distributionapplication 350 is shown in FIG. 3 as residing in the storage 310 of theDNN 120, all or portions of the LCR distribution application 350 may bestored on, downloaded to, and/or executed on another network resourceincluding the DVS 110, the UVS 102, or elsewhere. The VP logic module390 coordinates the interactions of the DNN 120 with one or more of theVPs 190. In alternative embodiments, the LCR distribution application350 may be included in the VP logic module 390. The DNN 120 furtherincludes an IP-routing module 330 suitable for implementing anIP-compliant routing mechanism.

Referring to FIG. 4, a block diagram of selected elements of aparticular embodiment of the VP 190 of FIG. 1 is depicted. The VP 190includes a processor 401 coupled via a shared bus 402 to storage mediacollectively identified at storage 410. The processor 401 may be ageneral purpose microprocessor such as an x86 type processor. In otherembodiments, the processor 401 may be implemented with any of various,commercially distributed embedded processors. The storage 410encompasses persistent and volatile media, fixed and movable media, andmagnetic and semiconductor media. The storage 410 is operable to storeinstructions, data structures, or any combination thereof. Sets ofinstructions stored in the storage 410 may be referred to as computerprograms, application programs, software, and other terms that will befamiliar to skilled artisans. Moreover, although the storage 410 isshown in FIG. 4 as an element of the VP 190, the storage 410 may includeportions that are distributed, network hosted, or otherwise remotelylocated from the VP 190.

The VP 190 as shown in FIG. 4 further includes a network adapter 420through which the VP 190 receives and transmits multimedia content. Inembodiments employing IP-based networks, multimedia content may bedelivered to the VP 190 as a series of IP-compliant packets. In otherembodiments, including digitally modulated cable-based embodiments ofthe access network 130 of FIG. 1, the multimedia content may bemodulated into a particular frequency band and transportedsimultaneously with multimedia content from other “channels,” which aremodulated into their own respective carrier bands.

The storage 410 shown in FIG. 4 includes software in the form of anoperating system (OS) 412, an LCR client application (LCR client app)414, and a virtual peer (VP) logic module 490. The OS 412 may representa Unix or Unix-like operating system, a Windows® family operatingsystem, or another suitable operating system. In some embodiments, theLCR client application 414 includes instructions that, when executed,cause two or possibly more of the CPE devices 140 and/or the VPs 190 todeliver multimedia content from at least one of the CPE devices 140and/or the VPs 190 to at least one other of the CPE devices 140 and/orthe VPs 190. In some embodiments, the delivery of multimedia contenttakes place entirely over a portion of the multimedia distributionnetwork 100 of FIG. 1 that is downstream of the DNNs 120. The LCR clientapplication 414 receives the multimedia content from a server, such asthe DVS 110. The LCR client application 414 stores the multimediacontent in the storage 410, receives a first request for multimediacontent by a first CPE device 140, and transmits the multimedia contentto the first CPE device 140.

In some embodiments, the VP logic module 490 includes instructions that,when executed, cause the VP 190 to transmit multimedia content to one ormore of the CPE devices 140 and/or the VPs 190. The VP logic module 490coordinates the interactions of each one of the VPs 190 with one or moreof the other VPs 190, with the CPE devices 140, and with the DNNs 120.In alternative embodiments, the LCR client application 414 may beincluded in the VP logic module 490. Implementing the LCR algorithmusing the VPs 190 helps prevent some of the drawbacks of a P2Pdistribution using an LCR algorithm. The P2P distribution using an LCRalgorithm relies on peers, such as the CPE devices 140, to storeportions of multimedia content and to transmit the stored portions toother peers. However, reliance on peers in the P2P scheme involveslimitations such as limited peer uplink bandwidth, peer storage needs,the impact of peer failures, and lack of transparency. The storagecapacity and the uplink capacity of the VPs 190 may be used in thedistribution of multimedia content. The VPs 190 may implement the LCRfunctions of peer storage and uploading to a peer and related controlfunctions so that the LCR algorithm is under the control of themultimedia distribution network 100. Use of network resources tofunction as virtual peers may eliminate uncertainties related to peeravailability, peer storage limitations, and peer uplink bandwidthrestraints that may be present in a P2P implementation of an LCRalgorithm. A VP implementation of an LCR algorithm increases reliabilitybecause the VPs 190 may be centrally powered and users may not affectthe downtime of the VPs 190. In an alternative embodiment where localaccess is through a wireless network, in addition to link capacities,signal quality (error rates) and signal strength may also play a role inlimiting a P2P implementation of an LCR algorithm, whereas a VPimplementation of an LCR algorithm may be less affected byconsiderations of signal quality (error rates) and signal strength.

Referring to FIG. 5, an illustration of limited chain relay (LCR)distribution not involving a helper virtual peer (VP) is depicted andgenerally designated 500. A helper VP is a VP that helps transfermultimedia content from one CPE device to another CPE device. In FIG. 5,lines terminating in black arrowheads represent message transfers whilelines terminating in white arrowheads represent multimedia contenttransfers. In the sequence 500, CPE1 540, which is the CPE device of afirst end user or first requestor, generates a content request at 502for a particular program of multimedia content (PMC). The contentrequest at 502 is the first content request that has occurred during thecurrent LCR interval of duration T and occurs before T/4. The contentrequest is transmitted 504 through an intervening DNN 548 and sent 506through a VP located at the network node (VPNN) 550 and forwarded 590 toa video server (VS) 552.

The VS 552 recognizes the content request as the first request for thePMC within the LCR interval and responds by transmitting the PMC to theCPE1 540 through the intervening VPNN 550 and DNN 548, as represented bythe arrows 592, 510, and 512. At the end of this portion of the sequence500, also before T/4, the CPE1 540 has stored all or some of the PMC.

When a subsequent request for the PMC is issued by CPE2 544, which isthe CPE device of a second end user or second requestor, at 520, thesubsequent request is transmitted through the DNN 548 to the VPNN 550 bymessages 522 and 524, between T/4 and T/2. The VPNN 550 may thendetermine that this subsequent request is not the first request for thePMC during this LCR interval of duration T. In this case, the VPNN 550will direct the CPEs involved to coordinate LCR distribution of the PMCfrom one CPE device to another.

As shown in FIG. 5, the VPNN 550 sends messages 526 and 528 to the CPE1540 through the DNN 548, between T/2 and 3T/4. Although FIG. 5illustrates the VPNN 550 coordinating the LCR distribution by sendingthe messages 526 and 528, other embodiments may delegate the managementof LCR distribution to the DNN 548 or to the VS 552 or to anothernetwork element not depicted in FIG. 5. The messages 526 and 528 informthe DNN 548 and the CPE1 540 that the subsequent request has been servedto at least one previous requestor during the current LCR interval ofduration T and indicate the identity of the previous requestor, which isthe immediately preceding requestor in some embodiments.

The DNN 548 determines from the messages 526 and 528 that the second PMCrequest may be served to the CPE2 544 by the CPE1 540 without the use ofa helper VP, such as VP1 542 and VP2 546. In this example, the uplinkcapacity of the CPE1 540 is sufficient to deliver the PMC to the CPE2544 without using the uplink capacity of VP1 542, which simplifies thedelivery of the PMC. In this example, the CPE1 540 begins to deliver thePMC to the CPE2 544 through the intervening DNN 548 as represented byarrow 530, between T/2 and 3T/4 and by arrow 532, between 3T/4 and T. Itwill be appreciated by those skilled in networked data transfer that thesecond request for the PMC is effectively served by the first requestorof the PMC. Moreover, the PMC delivery that occurs does not require useof network elements more upstream than the access network 130 of FIG. 1.For example, the VPNN 550 that directs the CPE1 540 to coordinate LCRdistribution of the PMC from the CPE1 540 to the CPE2 544 is included inthe access network 130.

Referring to FIG. 6, an illustration of LCR distribution that doesinvolve a helper VP is depicted and generally designated 600. In FIG. 6,lines terminating in black arrowheads represent message transfers whilelines terminating in white arrowheads represent multimedia contenttransfers. The CPE1 640 issues a PMC request 602 that is the first PMCrequest of the current LCR interval of duration T, the PMC request 602occurring before T/4. The uplink capacity of the CPE1 640 or anotherdevice that participates in the PMC transfer is measured and it isdetermined that the bandwidth constraints are too severe. The sequence600 addresses this scenario by identifying and selecting a helper VP(e.g., VP1 642) from a pool of available helper VPs in response to thePMC request. The selection of helper VPs may be facilitated by selectinghelper VPs based on availability factors, capacity factors, current orrecent activity factors, and so forth.

The PMC request is routed by multimedia servers to VS 652 via DNN 648and VPNN 650 as represented by the arrows 602, 604, and 690. The VS 652responds to the PMC request and the helper VP selection by deliveringthe PMC to the VP1 642 as well as to the CPE1 640 by arrows 692, 610,and 612, also occurring before T/4. The arrow 612 illustrates contenttransfer that occurs by multicasting to the CPE1 640 and the VP1 642.

When a second request for the PMC is detected within the same LCRinterval of duration T as the first request, CPE2 644 transmits thesecond request to the VPNN 650 using messages 620 and 622, occurringbetween T/4 and T/2. The VPNN 650 determines that this subsequentrequest for the PMC may be serviced by downstream elements because thePMC has been stored on the CPE1 640 and the VP1 642. Accordingly, theVPNN 650 sends a message to the CPE1 640 and the VP1 642 via arrows 624and 626, between T/2 and 3T/4, indicating the identity of the secondrequestor, the CPE2 644. The CPE1 640 and the VP1 642 respond bycooperatively or jointly transmitting content 628, between T/2 and 3T/4,from the CPE1 640 and the VP1 542 through the DNN 648 and thendelivering 630, between 3T/4 and T, the content to the CPE2 644 and to anewly selected helper VP, VP2 646. The VP2 646 represents the helper VPthat may help deliver content to a third requestor of the PMC during thecurrent LCR interval of duration T. In this example, unlike the exampleshown in FIG. 5, the uplink capacity of the CPE1 640 is insufficient todeliver the PMC to the CPE2 644 without using the uplink capacity of thefirst virtual peer VP1 642. The uplink capacity of the first virtualpeer VP1 642 may be used to help deliver the PMC to the CPE2 644 and tothe second virtual peer VP2 646. In this way, the PMC may be delivereddespite the insufficient uplink capacity of the CPE1 640.

Referring to FIG. 7, a flow diagram of selected elements of a particularembodiment of a method of distributing multimedia content is depictedand generally designated 700. The method 700 emphasizes LCR distributionof multimedia content with or without the use of helper VPs. In someembodiments, the method 700 is illustrative of computer executableinstructions that are stored in or otherwise embedded in a computerreadable medium such as the computer readable medium of the DNN 120 ofFIG. 1, the VP 190, or other network resource suitable for managing LCRchaining

The method 700 segments time into intervals of a predetermined durationT. The method 700 is an iterative method that repeats on each successiveinterval. The time intervals may be referred to as LCR intervals. Forexample, FIG. 5 and FIG. 6 illustrate activities that occur within anLCR interval of duration T.

In block 702, an initial or a subsequent time interval of duration T isbegun. As part of the start of a new LCR interval, the method 700includes, at block 703, evaluating the uplink capacity of the CPE deviceto determine whether helper VPs are going to be necessary to achieveadequate bandwidth for chain relaying distribution. If the uplinkcapacity of the CPE device is insufficient to deliver a particularprogram of multimedia content (PMC), one or more helper VPs may beneeded to help deliver the PMC, as in the example of FIG. 6. In someembodiments, link capacity is evaluated only after receiving a requestfor content. These embodiments have the benefit of knowing preciselywhich CPE device is being employed and the uplink evaluation may occuron the CPE device of interest. In other embodiments, the uplink capacityis evaluated based on an exemplary or typical CPE device. The uplinkevaluation may return information including information indicative ofhow many helper VPs might be needed. Additional details of the uplinkevaluation 703 are described below with respect to FIG. 8.

After initializing the LCR interval and evaluating the CPE device uplinkcapacity, the method 700 includes detecting a first end user request fora specific PMC and, in response downloading the PMC from a video servervia a virtual peer located at a network node to the requestor's CPEdevice and to any helper VPs as needed, at 704. If no helper VPs areneeded, the PMC is downloaded to the requestor's CPE device. Thedownloaded PMC is stored on the first requestor's CPE device and on anyhelper VPs as needed, at 706. If no helper VPs are needed, the PMC isstored on the requestor's CPE device.

If the method 700 has determined in block 703 that one or more helperVPs would be needed to support LCR distribution of multimedia content,block 704 would include selecting any needed helper VPs from a pool ofavailable helper VPs and delivering at least some portion of the PMC tothe one or more helper VPs. When helper VPs are involved in the LCRdistribution, delivering a PMC to a requesting CPE device and to one ormore helper VPs may include multicasting the PMC to the requestor andthe one or more helper VPs.

After servicing the initial request for content, the method 700 includesmonitoring the CPE devices 140 of FIG. 1 for a subsequent request forthe PMC, at 708. If the current LCR interval expires, at 710, before asubsequent request for the PMC is detected, the method 700 returns toblock 702 where a new LCR interval is initiated. If, in block 710, thecurrent LCR interval has not expired, the method 700 determines, atblock 712, whether a subsequent request for the PMC has been detected.If a subsequent request for the PMC has not been detected, the method700 returns to block 708. If a subsequent request for the PMC has beendetected, the method 700 responds to the subsequent request in block 720by selecting helper VPs, if necessary, and delivering at least some ofthe PMC from a previous CPE device and from any helper VPs that wereassociated with the previous requestor's CPE device to the currentrequestor's CPE device and to any helper VPs that are associated withthe current requestor's CPE device. It should be noted that differentresources may send content at different rates to the next successiverequestor. For example, a CPE device receiving content from the previousrequestor CPE device and two helper VPs may obtain 70% of the contentfrom the first helper VP, 20% of the content from the second helper VP,and 10% of the content from the previous requestor CPE device.

In block 721, the method 700 monitors for completion of the delivery ofcontent by the one or more selected helper VPs associated with aprevious requestor CPE device and, when delivery is complete, releasesthe applicable helper VPs back into the helper VP pool where the helperVPs are available to help subsequent requestor CPEs. By releasing andrecycling helper VPs as soon as possible, as soon as the helper VPs havedelivered the necessary content to the current requestor CPE, the method700 may be able to operate with fewer total helper VPs than otherwise.

The delivery of multimedia content in block 720 from one CPE device toanother CPE device occurs over downstream portions of the multimediadistribution network 100 of FIG. 1. Specifically, intra-CPE contentdelivery occurs on portions of the multimedia distribution network 100that are downstream of the video servers UVS 102 and DVS 110. Bydelegating content transfer to downstream portions of the multimediadistribution network 100, LCR distribution of content beneficiallyconserves bandwidth and processing resources of the video servers,thereby enabling the video servers to serve a greater number of contentrequests at lower processing overhead. In come embodiments, LCRdistribution of content between CPE devices may still requireadministrative participation of a video server or a virtual peer. Forexample, a video server or a virtual peer may be required to respond tosubsequent content requests by coordinating messages to the DNNs 120 ofFIG. 1 and the CPE devices 140 to facilitate the intra-CPE contenttransfer.

Referring to FIG. 8, a flow diagram of selected elements of a particularembodiment of a method of evaluating an uplink of a CPE device isdepicted and generally designated 800, corresponding to block 703 inFIG. 7. The uplink evaluation method 800 includes determining an uplinkcapacity of the CPEs and the DNNs, at 802. If the uplink capacity issufficient in block 804, then the uplink evaluation method 800determines, at 808, whether the CPE device uplink capacity is excessivesuch that the uplink bandwidth capacity exceeds the bandwidthrequirement needed to transfer multimedia content. If the CPE deviceuplink capacity is excessive, the number of subsequent requestors that asingle uplink may service is determined, at 810, and the uplinkevaluation method 800 terminates. If the CPE device uplink capacity isnot excessive, the uplink evaluation method 800 terminates. If theuplink capacity is not sufficient in block 804, the uplink evaluationmethod 800 includes determining, at 806, a required number of helper VPsto be used and then the uplink evaluation method 800 terminates.

Referring to FIG. 9, a flow diagram of selected elements of a particularembodiment of a method of providing a limited chain relay (LCR) with atleast one virtual peer for multimedia distribution is illustrated and isgenerally designated 900. The method 900 includes at first customerpremises equipment (CPE) coupled to a multimedia distribution network,generating a first request for multimedia content, at 902. For example,at a first CPE device 140 of FIG. 1 coupled to the multimediadistribution network 100, a first request for multimedia content may begenerated. The method 900 also includes sending the first request to anetwork node of the multimedia distribution network, at 904. Forexample, the first request for multimedia content may be sent to a DNN120 of FIG. 1.

The method 900 further includes receiving the multimedia content from avirtual peer located at the network node, at 906, and storing themultimedia content at the first CPE, at 908. For example, the multimediacontent may be received from a VP 190 of FIG. 1 located at the DNN 120and the multimedia content may be stored at the first CPE device 140 inthe storage 210 of FIG. 2. The method 900 also includes receiving amessage via the multimedia distribution network, the message indicatinga transmission of a second request for the multimedia content by asecond customer premises equipment (CPE) device, at 910. For example, amessage may be received via the multimedia distribution network 100 ofFIG. 1, the message indicating a transmission of a second request forthe multimedia content by a second CPE device 140.

The method 900 further includes transmitting at least a portion of thestored multimedia content to the second CPE, at 912. For example, atleast a portion of the multimedia content stored at the first CPE device140 of FIG. 1 in the storage 210 of FIG. 2 may be transmitted to thesecond CPE device 140 via a router 122 of one of the DNNs 120.

In a particular embodiment, the VP 190 of FIG. 1 includes the processor401 of FIG. 4, a computer readable storage medium, such as the storage410, accessible to the processor 401, and a network interface, such asthe network adapter 420, for receiving the multimedia content. Thestorage 410 includes instructions including an LCR application, such asthe LCR client application 414. In alternative embodiments, the LCRapplication may be included in the LCR logic module 490. The LCRapplication enables the VP 190 to receive the multimedia content from aserver, such as the DVS 110, and store the multimedia content in thestorage 410, receive the first request for the multimedia content by thefirst CPE device 140, and transmit the multimedia content to the firstCPE device 140. In a particular embodiment, the VP 190 at the DNN 120emulates the first CPE device and executes the LCR application. In aparticular embodiment, the VP 190 at the DNN 120 appears to the firstCPE device 140 to be another customer premises equipment (CPE) device(i.e., another peer) executing the LCR application.

In an alternative embodiment, the VP 190 is a process (computerprogram/process/thread) implementing an LCR algorithm. The VP 190 may becreated and destroyed as needed, particularly when the VP 190 is aprocess. For example, with each arrival of a request for multimediacontent, a VP 190 may be created at the DNN 120, or at an adjunctthereof, implementing an LCR algorithm to handle the peer functions topatch the next arrival, if any, of a request for the same multimediacontent. The created VP 190 will be finished handling the peer functionsof patching by the end of the next LCR interval of duration T after theVP 190 was created, because the maximum time in which patching is doneis one LCR interval of duration T. In a particular embodiment, allpatching in an LCR algorithm is handled by the VP 190 and no real peeris involved in the patching process, removing dependence on the CPEdevice 140. The residence of the VP 190 at the DNN 120 allows the VP 190to communicate with the network adapter at high speed, removing thebandwidth-related issues of a real peer. The ability to implement an LCRalgorithm in the DNN 120 through the VPs 190 also provides the abilityto benefit from concurrence of demands for the same multimedia contentbecause the DNNs 120 have better connectivity between each other, interms of available bandwidth and the like, than real peers. A P2Pimplementation of an LCR algorithm may be hampered because the DSLAMsare not generally interconnected, with each DSLAM having a small numberof customers to obtain a required concurrency of demands, and even whenDSLAMs are connected, two access links may have to be used to effectpatching to a peer residing under a different DSLAM.

In a particular embodiment, the CPE device 140 of FIG. 1 is a set-topbox device (STB). In a particular embodiment, transmitting at least aportion of the stored multimedia content from the first CPE device 140to the second CPE device 140 includes routing at least a portion of thestored multimedia content through the DNN 120, via the router 122, tothe second CPE device 140. In a particular embodiment, the DNN 120comprises one of a central office (CO) node and a digital subscriberline access multiplexer (DSLAM) node.

In a particular embodiment, a connection between the first CPE device140 of FIG. 1 and the DNN 120 includes a downlink and an uplink. In suchan embodiment, the method 900 further includes, whenever a bandwidthcapacity of the uplink is less than a predetermined threshold,determining a number of first helper VPs 190 needed to transmit themultimedia content, selecting the first helper VPs 190 from a pool ofavailable helper VPs 190, transmitting at least some of the multimediacontent from the VP 190 to the selected first helper VPs 190, andstoring at least some of the multimedia content at the selected firsthelper VPs 190. Transmitting at least a portion of the stored multimediacontent to the second CPE device 140 further includes transmitting atleast some of the stored multimedia content from the selected firsthelper VPs 190 to the second CPE device 140.

In such an embodiment, the method 900 further includes selecting anumber of second helper VPs 190 of FIG. 1 and transmitting at least someof the stored multimedia content to the second helper VPs 190. In suchan embodiment, the method 900 further includes maintaining the pool ofavailable helper VPs 190 and selecting at least one helper VP 190 fromthe pool.

Selecting at least one helper VP 190 of FIG. 1 may include selecting atleast one helper VP 190 based, at least in part, on an expectedutilization of some of an uplink capacity of at least one helper VP 190.A maximum uplink capacity of the first CPE device 140 may be M1, amaximum uplink capacity of a first helper VP 190 may be M2, and anuplink capacity to deliver the multimedia content to the second CPEdevice 140 may be K and the number of first helper VPs 190 may bedetermined based, at least in part, on M1, M2, and K. For example, whenM1 is substantially equal to M2, a minimum number of first helper VPs190 may be greater than or equal to (K/M1)−1. If K is substantiallyequal to M1, a minimum number of first helper VPs 190 may be zero and nofirst helper VPs 190 may be needed. A number of first helper VPs 190exceeding the minimum may be selected where at least some of theselected first helper VPs 190 may be used to provide redundancy in caseof a failure of another first helper VP 190.

In embodiments where helper VPs 190 of FIG. 1 may be needed, the firstCPE device 140 and the second CPE device 140 may be limited to storingonly a portion of the multimedia content. In a particular embodiment,the multimedia content includes video-on-demand (VOD) content. In a VODoffering, stream control events, such as fast forward, rewind, replay,skip and the like, are generated from user interactions. A VPimplementation of an LCR algorithm facilitates stream controloperations. For example, a fast forward operation would seek to thecorrect time segment of a movie provided by a VP and uploaded to therequesting client. A VP implementation of an LCR algorithm makes thisoperation more efficient because the multimedia content being sought isin a disk cache situated at a central office (CO), for example.

The CPE device 140 of FIG. 1 may include the processor 201 of FIG. 2, acomputer readable storage medium, such as the storage 210, accessible tothe processor 201, a network interface, such as the network adapter 220,for receiving the multimedia content, and the decoder 240 for processingthe multimedia content received via the network interface. The storage210 includes instructions including an LCR application, such as the LCRclient application 214. In alternative embodiments, the LCR applicationmay be included in the LCR logic module 290. The LCR application enablesthe CPE device 140 to generate a first request for the multimediacontent and send the first request to the VP 190 via the DNN 120 of themultimedia content distribution network 100 coupled to a server, such asthe DVS 110, receive the multimedia content from the VP 190 via the DNN120 and store the received multimedia content, receive a messageindicating a transmission of a second request for the multimedia contentby the second CPE device 140, and, in response to receiving the message,transmit at least a portion of the stored multimedia content to thesecond CPE device 140 via the DNN 120.

In a particular embodiment, when an uplink capacity of a connectionbetween the CPE device 140 and the DNN 120 is less than a predeterminedcapacity necessary to sustain video content delivery, the CPE device 140is further configured to respond to the second request by selecting oneor more first helper VPs 190 from a pool of available helper VPs 190 andtransmitting at least a portion of the stored multimedia content to thesecond CPE device 140 and to at least one second helper VP 190. In aparticular embodiment, selecting one or more first helper VPs 190includes selecting one or more wireless first helper VPs 190.

The DNN 120 of FIG. 1 may include the processor 301 of FIG. 3, acomputer readable storage medium, such as the storage 310, accessible tothe processor 301, and a network interface, such as the NIC 320, forreceiving the multimedia content. The storage 310 includes instructionsincluding an LCR distribution application, such as the LCR distributionapp 350. In alternative embodiments, the LCR distribution applicationmay be included in the LCR logic module 390. The LCR distributionapplication enables the DNN 120 to determine a beginning and ending ofsuccessive LCR time intervals, responsive to detecting a first requestduring a first LCR time interval, where the first request is for themultimedia content, transmit at least a portion of the multimediacontent to the first CPE device 140, and, responsive to detecting asecond request during the first LCR time interval, where the secondrequest is also for the multimedia content, send a message to the firstCPE device 140 instructing the first CPE device 140 to transmit at leasta portion of the multimedia content from the first CPE device 140 to thesecond CPE device 140. In a particular embodiment, at least one VP 190is located at the DNN 120.

Referring to FIG. 10, an illustrative embodiment of a general computersystem is shown and is designated 1000. The computer system 1000includes a set of instructions that can be executed to cause thecomputer system 1000 to perform any one or more of the methods orcomputer based functions disclosed herein. The computer system 1000, orany portion thereof, may operate as a standalone device or may beconnected, e.g., using a network, to other computer systems orperipheral devices.

In a networked deployment, the computer system 1000 may operate in thecapacity of a set-top box device, a server, or a mobile computingdevice, such as the UVS 102 of FIG. 1, the DVSs 110 of FIG. 1, the DNNs120 of FIG. 1 and FIG. 3, the VPs 190 of FIG. 1 and FIG. 4, the CPEdevices 140 of FIG. 1 and FIG. 2, the backbone network 104 of FIG. 1,the access network 130 of FIG. 1, and the home network 150 of FIG. 1.The computer system 1000 can also be implemented as or incorporated intovarious devices, such as a personal computer (PC), a tablet PC, apersonal digital assistant (PDA), a mobile device, a palmtop computer, alaptop computer, a desktop computer, a communications device, a webappliance, or any other machine capable of executing a set ofinstructions (sequential or otherwise) that specify actions to be takenby that machine. In a particular embodiment, the computer system 1000can be implemented using electronic devices that provide voice, video ordata communication. Further, while a single computer system 1000 isillustrated, the term “system” shall also be taken to include anycollection of systems or sub-systems that individually or jointlyexecute a set, or multiple sets, of instructions to perform one or morecomputer functions.

As illustrated in FIG. 10, the computer system 1000 may include aprocessor 1002, e.g., a central processing unit (CPU), agraphics-processing unit (GPU), or both. Moreover, the computer system1000 can include a main memory 1004 and a static memory 1006 that cancommunicate with each other via a bus 1008. As shown, the computersystem 1000 may further include or be coupled to a video display unit1010, such as a liquid crystal display (LCD), an organic light emittingdiode (OLED), a flat panel display, a cathode ray tube (CRT) display, asolid-state display, or a projection display. Additionally, the computersystem 1000 may include an input device 1012, such as a keyboard, aremote control device, and a cursor control device 1014, such as amouse. The computer system 1000 can also include a disk drive unit 1016,a signal generation device 1018, such as a speaker or remote controldevice, and a network interface device 1020. The network interfacedevice 1020 may be coupled to other devices (not shown) via a network1026.

In a particular embodiment, as depicted in FIG. 10, the disk drive unit1016 may include a computer-readable medium 1022 in which one or moresets of instructions 1024, e.g., software, can be embedded. Further, theinstructions 1024 may embody one or more of the methods or logic asdescribed herein. In a particular embodiment, the instructions 1024 mayreside completely, or at least partially, within the main memory 1004,the static memory 1006, and/or within the processor 1002 duringexecution by the computer system 1000. The main memory 1004 and theprocessor 1002 also may include computer-readable media.

In an alternative embodiment, dedicated hardware implementations, suchas application-specific integrated circuits, programmable logic arraysand other hardware devices, can be constructed to implement one or moreof the methods described herein. Applications that may include theapparatus and systems of various embodiments can broadly include avariety of electronic and computer systems. One or more embodimentsdescribed herein may implement functions using two or more specificinterconnected hardware modules or devices with related control and datasignals that can be communicated between and through the modules, or asportions of an application-specific integrated circuit. Accordingly, thepresent system encompasses software, firmware, and hardwareimplementations.

In accordance with various embodiments of the present disclosure, themethods described herein may be implemented by software programsexecutable by a computer system. Further, in an exemplary, non-limitedembodiment, implementations can include distributed processing,component/item distributed processing, and parallel processing.Alternatively, virtual computer system processing can be constructed toimplement one or more of the methods or functionalities as describedherein.

The present disclosure contemplates a computer-readable medium thatincludes instructions 1024 or receives and executes instructions 1024responsive to a propagated signal, so that a device connected to anetwork 1026 can communicate voice, video, or data over the network1026. Further, the instructions 1024 may be transmitted or received overthe network 1026 via the network interface device 1020.

While the computer-readable medium is shown to be a single medium, theterm “computer-readable medium” includes a single medium or multiplemedia, such as a centralized or distributed database, and/or associatedcaches and servers that store one or more sets of instructions. The term“computer-readable medium” shall also include any medium that is capableof storing or encoding a set of instructions for execution by aprocessor or that cause a computer system to perform any one or more ofthe methods or operations disclosed herein.

In a particular non-limiting, exemplary embodiment, thecomputer-readable medium can include a solid-state memory such as amemory card or other package that houses one or more non-volatileread-only memories. Further, the computer-readable medium can be arandom access memory or other volatile re-writable memory. Additionally,the computer-readable medium can include a magneto-optical or opticalmedium, such as a disk or tapes or other storage device to capturecarrier wave signals such as a signal communicated over a transmissionmedium. A digital file attachment to an email or other self-containedinformation archive or set of archives may be considered equivalent to atangible storage medium. Accordingly, the disclosure is considered toinclude any one or more of a computer-readable storage medium and otherequivalents and successor media, in which data or instructions may bestored.

It should also be noted that software that implements the disclosedmethods may optionally be stored on a tangible storage medium, such as:a magnetic medium, such as a disk or tape; a magneto-optical or opticalmedium, such as a disk; or a solid state medium, such as a memory cardor other package that houses one or more read-only (non-volatile)memories, random access memories, or other re-writable (volatile)memories.

Although the present specification describes components and functionsthat may be implemented in particular embodiments with reference toparticular standards and protocols, the invention is not limited to suchstandards and protocols. For example, standards for Internet, otherpacket switched network transmission (e.g., TCP/IP, UDP/IP, HTML, andHTTP) and standards for viewing media content (e.g., MPEG, SMPTE, andH.264) represent examples of the state of the art. Such standards areperiodically superseded by faster or more efficient equivalents havingessentially the same functions. Accordingly, replacement standards andprotocols having the same or similar functions as those disclosed hereinare considered equivalents thereof.

One or more embodiments of the disclosure may be referred to herein,individually and/or collectively, by the term “invention” merely forconvenience and without intending to voluntarily limit the scope of thisapplication to any particular invention or inventive concept. Moreover,although specific embodiments have been illustrated and describedherein, it should be appreciated that any subsequent arrangementdesigned to achieve the same or similar purpose may be substituted forthe specific embodiments shown. This disclosure is intended to cover anyand all subsequent adaptations or variations of various embodiments.Combinations of the above embodiments, and other embodiments notspecifically described herein, will be apparent to those of skill in theart upon reviewing the description.

The Abstract of the Disclosure is submitted with the understanding thatit will not be used to interpret or limit the scope or meaning of theclaims. In addition, in the foregoing Detailed Description, variousfeatures may be grouped together or described in a single embodiment forthe purpose of streamlining the disclosure. This disclosure is not to beinterpreted as reflecting an intention that the claimed embodimentsrequire more features than are expressly recited in each claim. Rather,as the following claims reflect, inventive subject matter may bedirected to less than all of the features of any of the disclosedembodiments. Thus, the following claims are incorporated into theDetailed Description, with each claim standing on its own as definingseparately claimed subject matter.

The above-disclosed subject matter is to be considered illustrative, andnot restrictive, and the appended claims are intended to cover all suchmodifications, enhancements, and other embodiments, which fall withinthe scope of the present invention. Thus, to the maximum extent allowedby law, the scope of the present invention is to be determined by thebroadest permissible interpretation of the following claims and theirequivalents, and shall not be restricted or limited by the foregoingdetailed description.

1. A method comprising: at a first customer premises equipment (CPE)device coupled to a multimedia distribution network, generating a firstrequest for multimedia content; sending the first request to a networknode of the multimedia distribution network; receiving the multimediacontent from a virtual peer located at the network node; storing themultimedia content at the first CPE device; receiving a message via themultimedia distribution network, the message indicating a transmissionof a second request for the multimedia content by a second customerpremises equipment (CPE) device; and transmitting at least a portion ofthe stored multimedia content to the second CPE device.
 2. The method ofclaim 1, wherein the virtual peer comprises: a processor and a computerreadable storage medium accessible to the processor; and a networkinterface for receiving the multimedia content; wherein the storagemedium includes instructions comprising a limited chain relay (LCR)application, the LCR application enabling the virtual peer to: receivethe multimedia content from a server and store the multimedia content inthe storage medium; receive the first request for the multimedia contentby the first CPE device; and transmit the multimedia content to thefirst CPE device.
 3. The method of claim 2, wherein the virtual peer atthe network node appears to the first CPE device to be another customerpremises equipment (CPE) device executing the LCR application.
 4. Themethod of claim 1, wherein the first CPE device is a set-top box device.5. The method of claim 1, wherein transmitting the at least a portion ofthe stored multimedia content from the first CPE device to the secondCPE device includes routing the at least a portion of the storedmultimedia content through the network node to the second CPE device. 6.The method of claim 1, wherein the network node comprises one of acentral office node and a digital subscriber line access multiplexernode.
 7. The method of claim 1, wherein a connection between the firstCPE device and the network node includes a downlink and an uplink andwherein the method further comprises: whenever a bandwidth capacity ofthe uplink is less than a predetermined threshold: determining a numberof first helper virtual peers needed to transmit the multimedia content;selecting the first helper virtual peers from a pool of available helpervirtual peers; transmitting at least some of the multimedia content fromthe virtual peer to the selected first helper virtual peers; and storingthe at least some of the multimedia content at the selected first helpervirtual peers, wherein transmitting the at least a portion of the storedmultimedia content to the second CPE device further comprisestransmitting the at least some of the stored multimedia content from theselected first helper virtual peers to the second CPE device.
 8. Themethod of claim 7, further comprising selecting a number of secondhelper virtual peers and transmitting the at least some of the storedmultimedia content to the second helper virtual peers.
 9. The method ofclaim 7, further comprising maintaining the pool of available helpervirtual peers and selecting at least one helper virtual peer from thepool.
 10. The method of claim 9, wherein selecting the at least onehelper virtual peer includes selecting the at least one helper virtualpeer based, at least in part, on an expected utilization of some of anuplink capacity of the at least one helper virtual peer.
 11. The methodof claim 7, wherein a maximum uplink capacity of the first CPE device isM1, a maximum uplink capacity of a first helper virtual peer is M2, andan uplink capacity to deliver the multimedia content to the second CPEdevice is K and wherein the number of first helper virtual peers isdetermined based, at least in part, on M1, M2, and K.
 12. The method ofclaim 11, wherein M1 is substantially equal to M2 and wherein a minimumnumber of first helper virtual peers is greater than or equal to(K/M1)−1.
 13. The method of claim 12, further comprising selecting anumber of first helper virtual peers exceeding the minimum and whereinat least some of the selected first helper virtual peers are used toprovide redundancy in case of a failure of another first helper virtualpeer.
 14. The method of claim 7, wherein the first CPE device and thesecond CPE device are limited to storing only a portion of themultimedia content.
 15. The method of claim 1, wherein the multimediacontent comprises video-on-demand (VOD) content.
 16. A customer premisesequipment (CPE) device comprising: a processor and a computer readablestorage medium accessible to the processor; a network interface forreceiving multimedia content; and a decoder for processing themultimedia content received via the network interface; wherein thecomputer readable storage medium includes instructions comprising alimited chain relay (LCR) application, the LCR application to: generatea first request for the multimedia content and to send the first requestto a virtual peer via a network node of a multimedia contentdistribution network coupled to a server; receive the multimedia contentfrom the virtual peer via the network node and store the receivedmultimedia content; receive a message indicating a transmission of asecond request for the multimedia content by second customer premisesequipment (CPE); and in response to receiving the message, transmit atleast a portion of the stored multimedia content to the second CPEdevice via the network node.
 17. The CPE device of claim 16, wherein anuplink capacity of a connection between the CPE device and the networknode is less than a predetermined capacity necessary to sustain videocontent delivery and wherein the CPE device is further configured torespond to the second request by selecting one or more first helpervirtual peers from a pool of available helper virtual peers andtransmitting the at least a portion of the stored multimedia content tothe second CPE device and to at least one second helper virtual peer.18. The CPE device of claim 17, wherein selecting the one or more firsthelper virtual peers comprises selecting one or more wireless firsthelper virtual peers.
 19. A network node suitable for use in amultimedia content distribution network, the network node comprising: aprocessor and a computer readable storage medium accessible to theprocessor; and a network interface for receiving multimedia content;wherein the storage medium includes instructions comprising a limitedchain relay (LCR) distribution application, the LCR distributionapplication to: determine a beginning and ending of successive LCR timeintervals; in response to detecting a first request during a first LCRtime interval, wherein the first request is for the multimedia content,transmit at least a portion of the multimedia content to a firstcustomer premises equipment (CPE) device; and in response to detecting asecond request during the first LCR time interval, wherein the secondrequest is also for the multimedia content, send a message to the firstCPE device instructing the first CPE device to transmit the at least aportion of the multimedia content from the first CPE device to a secondcustomer premises equipment (CPE) device.
 20. The network node of claim19, wherein at least one virtual peer is located at the network node.